This invention relates to a method for calibration a measurement apparatus used for determining at least the pH and pCO.sub.2 values in aqueous media, and to an arrangement for implementation of this method.
Because of the interdependence between the pH and pCO.sub.2 values in aqueous media, a joint measurement of the two variables often is necessary in analytical chemistry. This applies in particular to biological systems in which CO.sub.2 is to be evaluated as a metabolic product and the pH value as a state variable of the organism that is maintained constant within relatively narrow limits.
An analytical problem of this type is the analysis of blood gas, in which pH, pCO.sub.2 and pO.sub.2 values are obtained in undiluted blood. The new calibrating method will be described below using blood gas analysis as an example, to which it is in no way restricted, however.